Pumping unit



June 30, 1964 c. SWANSON PUMPING UNIT 3 Sheets-Sheet 2 Filed Aug. 18, 1960 J n 30, 1964 E. c. SWANSON PUMPING UNIT 3 Sheets-Sheet 3 Filed Aug. 18, 1960 2 s a 7 a 3 i 4 7 United States Patent 3,139221 Patented June 30, 1964 PUMPING UNIT Edwin C. Swanson, Rockford, Ill., assignor to Gree'nlee Bros. & Co., a corporation of Illinois Filed Aug. 18, 1960, Ser. No. 50,517 8 Claims. (Cl. 222-255) This invention relates to a pumping unit and more par-- ticularly to a portable motor driven pumping unit for Operating hydraulic tools. V

It's the general object of the invention to provide a new and improved pumping unit of this character.

Another object is to provide a new and improved portable pumping unit which will automatically and successively provide a relatively high Volume, low pressure output or a relatively high pressure, 1ow Volume output for operatng a hydraulic tool, and which will maintain the high pressure on the tool upon the completion of a pressing or during any other holding operation.-

Another object is to provide such a unit embodying automatic control means for relieving the high pressure to release the tool. p v

Other objects and advantages will become apparent from the following detailed description of a `preferred embodiment of the invention taken in connection with the accompanying drawings, in which:

.FIG. 1 is a front elevational View of a preferred form of the invention, with a portion in section along the line 1-1 of FIG. 2. i

FIG. 2 is an elevational View looking at the right hand side of FIG. 1' and partly in section along the line 2-2 of FIG. 1.

FIG. 3 isa top plan view.

FIG. 4 is a fragmentary section along the line 4-4 of FIG. 2.

FIG. 5 is a fragmentary section along the line 5-5 of FIG. 2.

FIG. 6 is a fragmentary section along the line 6-6 of FIG. 1.

FIG. 7 is a fragmentary section along the line 7-7 'of FIGS. 2 and 3.

. FIG. '8 is a fragmentary section along the line 8-8 of FIG. 1.

While the invention is hereindescribed in a preferred embodiment, it is not intended to limit the invention to the specific form and arrangement shown, it being con templated that various changes may be made by those skilled in the art without departng from the spirit and scope of the appended claims.

In the form shown, the invention is embodied in a portable pumping unit which is adapted to be connected to a piston and cylinder device of a press or C clamp or the like, to automatically supply a relatively large Volume of fluid at a relatively low pressure for a rapid movement of the piston when the resistance to the movement thereof is low, and a small Volume of fluid at relatively high pressure for a slower movement of the piston when the resistance to its movement is high, and to hold the high pressure when so desired. Furthermore, the unit is of the electric motor driven type 'and is so constructed that upon starting the motor, when the unit is connected to such a hy draulic tool, it will automatically and successively provide a relatively high Volume, low pressure output followed by a relatively high pressure, low Volume output, and upon completing the operationof the tool and the stoppng of the drive motor, the pressure in the line to the tool will be automatically relieved so as to permit the tool to release itself.

As shown in the drawings, a rectangular casing 20 provides a reservoir 21, and has a top plate 22 (Secured to the reservoir by bolts 23) from which a pumping mechanism is Suspended. The pumping mechanism comprises a pump block 24 having an upper portion forming the top plate 22 and a lower portion 25 depending into the reservoir. A low pressure large Volume rotary pump 28 located at the bottom of the pump block and a high pressure small Volume piston pump 29 are driven by a vertical drive shaft 30 suitably connected to the shaft 'of an electric motor 31. A carrying handle 31' is attached to the top of the motor to facilitate handling the unit.

The rotary pump 28 may be of the gear tooth type illustrated best in FIGS. 1, 5 and 6, and has an inlet port 32 in a plate 32' and an outlet port 33. A strainer 34 (FIG. 1) covers the inlet to the port 32. In the preferred form of the invention this pump is designed to develop a pressure up to 1,000 pounds per square inch in the outlet port ata Volume of cubic inches of fluid per minute.

The piston pump 29 comprises a horizontally positioned piston 35 in a pump cylinder formed by a sleeve 36 and i a vbushing 37. A coiled spring 38 in the bushing acts against the adjacent end of the piston and urges it out wardly of the cylinder so that a head 39 on the piston rides on a needle hearing 40 carried on an eccentric 41 on the vertical shaft 30. A counterweight 41' on the' shaft balances the eccentric. The shaft is supported in antifriction bearings 42 and 43 in laterally extending portions 44 and 45 on the dependingportion 25 of the pump block. In the formshown the piston pump is designed to develop a pressure up to 10,000 pounds per square inch and a Volume of from 5 to 7 cubic inches of fluid per minute.

Fluid drawn by the rotary pump 28 from the reservoir 21 passes from the outlet port 33 (FIGS. 1 and 5) through a horizontal outlet passage 46 (FIGS.' 1,` 2 and 5) to a ver tical port 47, theupper end of which is controlled by a ball check valve 48 positioned in an enlarged* portion 49 of the port 47 adjacent the sleeve 36. As shown best in FIG. 5, a low pressure relief valve 46' is provided to limit the outlet pressure of the' low pressure pump in passage 46. The sleeve 36has radial ports 50 therein. An annular chamber Slaround the sleeve connects ports 50 with a vertical high pressure outlet port 52 which is enlarged to form a step 53 against which outlet check valve 54 seats. A spacing member in the form of a rod 55 fits loosely in 'the port 52 above the check valve and at its upper end is engaged by an adjustable screw 56 so that the distance the ball 54 can move upwardly from the seat 53 may be adjusted. 56" indicates a locknut for' the screw 56. The fluid passesupwardly between the rod and the wall of the port, and out through a transverse passage 57 to a discharge port 58 in which a pipe 59 is'secured. 60 indicates a hose fitting which is normally closed and pernits quick attachment of a hose carrying a complementary fitting.

As shown in FIG. 4, the side wall of the port 52 connects through a passage 61 to a high pressure relief valve 62 which discharges into the reservoir when the pressure exceeds its pre-adjusted value. Preferably, the

rod 55 has an annular groove 55' adjacent the port 61 to insure adequate communication between the port and the fluid passing upwardly in the port 52..

As shown somewhat diagrammatically in FIG. 2, a hose 65 connects the discharge fitting 60 and a cylinder 66 of a tool 67 which is moved'to a jaw closing position by a piston 68 in the cylinder. A coiled spring 69, fastened at one end to the piston at 70 and at its other end to the cylinder end at 71, operates to pull the piston towards the end of the cylinder whenever pump pressure is relieved in the connecting hose 65.

The form of the invention shown may be equipped with an automatic device to relieve the discharge pressure of the pump when the motor 31 is stopped, and thereby permit the clamp to open through the action of the spring 69, as without such a device the pressure' would be maintained in the hose 65. Such an automatic pressure relief device is shown in FIGS. 1, 2, 4 and and includes a bypass controlling ball valve 75 normally closing a high pressure fluid drain or bypass port 76. A lever 77 is pivoted on a pin 72 secured in laterally spaced lugs 79 and 80 on the pump block portion 25 and carries a screw 81, a projecting end of which engages against the ball valve 75. Preferably a lock nut 82 is provided on the screw. The lower end of the lever, as shown best in FIG. 2 engages the adjacent end 83 of a hollow piston 84 slidable in a horizontal cylinder bore 85 in the lower portion of the pump block. The cylinder bore intersects and communicates with the low pressure pump outlet passage 46 so that the low pressure fluid can pass through radial ports 86 in the piston 84 and act to' close a ball valve 87 against a seat 88 and prevent fluid from passing out through a longitudinal port 89 in the piston and transverse ports 90. A coiled spring 91 in the port 89 acts to unseat the valve 87 when the fluid pressure in the outlet passage of the low pressure pump drops, a cross pin 92 being provided to limit the movement of the valve away from the seat. A spring 99 between the upper end of lever 77 and the pump block maintains the lower end of the lever in contact with piston 84.

Preferably a manual control is also provided to relieve the* pressure in the high pressure line. Thus, as shown in FIG. 7, a drain port 93 communicates at one end with the high pressure fluid passage 57 and at its other end with a Vertical port 94 which discharges into the reservoir 21. A valve 95 controls the port 93 and is carried on a stern 96 provided with a screw thread 97 and a handle 98.

When provided with the automatic control, the pumping unit may be connected to a suitable source of electric power by means of an attachment plug 100 carried on the end of a line 101 and so arranged in a circuit with a switch 102 carried on an extension line 103 that 4, pumped by the low pressure pump then discharging to the reservoir by the low pressure relief valve 46'.

When the piston of the tool 67 has reached the end of its stroke the pressure against the tool may be maintained, if so desired. otherwise, to release the tool an operator, by disengaging the motor switch 104, stops the motor and the pump whereupon the pressure in the low pressure pump outlet passage 46 drops sufi'iciently to relieve the pressure against the valve 87 (FIG. 2) thus permittng the spring 91 to open valve 87 and drain fluid from the right hand end of the cylinder 85. This permits the spring 99 to pivot the lever 77 and open the valve 75 to drain fluid out of the port 76. This relieves the pressure in the line to the tool and against the piston-in the tool so that the spring 69 may withdraw the piston and release the tool.

As indicated hereinbefore, an alternate means for relieving the pressure in the line is shown in FIG. 7 in the form of a manually controlled valve 95.

By adjusting the screw 56, the upward movement of the rod 55 may be varied and this in turn changes the distance the valve 54 moves upwardly from its seat during a discharge stroke of the high pressure pump piston. This varies the output of the high pressure pump, the maximum output Volume being attained when the movement of valve 54 is relatively small. As the screw 56 is raised to permit the valve 54 to move farther from its seat, the valve moves farther from its seat during the discharge stroke of the pump piston and therefore takes longer to return to its seat during the early part of the next suction stroke of the pump piston. Thus there is some time for fluid tospill back over the valve during the suction stroke of the pump piston until the valve 54 closes.

I claim: p

1. A pumping apparatus comprising, in combination, a casing forming a reservoir and a pump block having a portion depending into the reservoir, an electric motor having a shaft extending into the reservoir, a low pressure rotary 'pump connected to the end of said shaft to be driven thereby and provided with an inlet passage upon Operating the switch handle 104 the motor 31 r may be started and stopped. When the motor is started, the low pressure pump 28 draws fluid out of the reservoir 21 and discharges it through the passage 46 and port 47 to the high pressure pump 29. If the resistance offered by the piston of the hydraulic tool 67 is relatively light and requires a pressure no greater than that determined by the low pressure relief valve 46' (FIG. 5), the relatively large Volume from the 'low pressure pump will pass the check valves 48 and 54 and discharge through the vertical ports and the passage 57 to the line port 58. When the resistance offered by the piston of the tool 67 increases so that the pressure of the low pressure pump is not sufficient to move it. the continuously Operating high pressure' piston 35 becomes operative to increase the pressure of the fluid discharged through the line port 58. At such time the output volume of the unit drops, the excess low pressure fluid for receiving fluid from'the reservoir and an outlet passage extending in the pump block, a high pressure piston pump having a cylinder positioned in said pump block, a piston in said cylinder and means on said shaft for reciprocating said piston, passages in said pump block forming inlet and outlet ports for said piston pump and having ball check valves therein; the inlet 'port connecting with the outlet passage of the low pressure pump, and means for adjusting the distance the outlet check valve can move from its seat during operation of the pumping apparatus.

2. A pumping apparatus comprising, in combination, a casing forming a reservoir, and a detachable pump block having an upper portion forming a top plate for the reservoir and a lower portion depending into the reservoir, 'an electric motor mounted on said top plate and having a shaft extending downwardly into the reservoir and through bearings 'supported on said pump block, a low pressure rotary pump connected to the lower end of said shaft to be driven thereby and provided with an inlet passage for receiving fluid from the reservoir and an outlet passage 'extending in the pump block, a high pressure piston pump having 'a cylinder positioned 'in said pump block, a piston in said cylinder and means on said shaft for reciprocating said piston, passages in said pump block forming inlet and outlet ports for said piston pump and having ball check valves therein, the inlet port connecting with the outlet passage of the low pressure pump, and means for adjusting the distance the outlet check valve can move from its seat during operation of the pumping apparatus comprising a screw threaded device in the pump block and aspacing member between said device and the outlet ball valve.

3. A pumping apparatus comprising, in combination, v

a casing forming a reservoir and a detachable pump block having an upper portion for-ming a top plate tor the reservoir and a lower portion depending into the res- 'ervoir, an electric motor mounted on said top plate and having ashaft extending downwardly into the reservoir and through bearings supported on said pump block, a low pressure rotary pump connected to the lower end of said shaft to be driven thereby and provided With an inlet passage for receiving fluid from the reservoir and an outlet passage extending in the pump block, a high pressure piston pump having a cylinder positioned in said pump block, a piston in said cylinder and an eccentric on said shaft for reciprocating said piston, passages in said pump block -forming inlet and outlet ports for said piston pump and having ball check valves therein, the inlet port connecting with the outlet passage of the low pressure pump, the outlet port extending upwardly to the top of the pump block, and means for adjusting the dise tance the outlet check valve can move from its seat during operation of the pumping apparatus comprising a screw threaded device in the upper portion of the pump block and a 'od loosely fitted in the high pressure outlet passage intermediate said screw threaded device and the outlet ball valve, and means operable when the pump s stopped for draining fluid from the high pressure pump' outlet passage to the reservoir.

4. A pumping apparatus comprising, in combination, a casing forming a reservoir open at the top, a pump block having a horizontal portion forming a top plate for the reservoir, a portion depending therefrom into the reservoir, and a pair of vertically spaced lateral extensions on said depending portion provided with aligned vertical bores, a motor mounted on said top plate and having a shaft extending down through said bores and to a position adjacent the bottom of the reservoir, bearings for said shaft mounted in said bores, a rotary low pressure pump supported on the bottom surface of the lower extension and driven by said shaft, said low pressure punp having an inlet port communicating with the reservoir and an outlet passage extending horizontally through said depending portion of the pump block, a

high pressure piston pump comprising a cylinder sleeve located in a bore extendng horizontally through the pump block and parallel with said outlet passage, a piston operable in said sleeve, an eccentric carried on said shaft intermediate said extensions for actuating said piston, a vertical passage extending upwardly from said horizontal outlet passage to the top of the pump block and having portions passing through said cylinder sleeve for delivering fluid from the rotary pump to the piston pump, an inlet check valve for the high pressure pump in said vertical passage below said sleeve, an outlet check valve for the high pressure pump in said Vertical passage above said sleeve and adapted to close against a seat in said passage, and means for varying the effective Volume of fluid discharged by the high pressure pump operable to adjust the distance the outlet check valve can move from its seat.

5. A- pump apparatus comprising, in combination, a casing forming a reservoir open at the.top, a pump block having a horizontal portion forming a top plate for the reservoir, a portion depending therefrom into the' reservoir, .and a pair of vertically spaced lateral extensions on said depending portion provided withaligned vertical bores, a motor mounted on said top plate and having a shaft extending down through said bores and to a position adjacent the bottom of the reservoir, a rotary low pressure pump supported on the bottom surface of the lower extension and driven by said shaft, said low pressure pump having an inlet port communicating with the reservoir and an outlet passage extending horizontally through said depending portion of the pump block, a high pressure piston pump comprising a cylinder formed 'u a sleeve located in a bore extending horizontally through the pump block and parallel with "said outlet passage, a piston operable in said sleeve, an 'eccentric carried on said shaft intermediate said extensions for actuatingsad piston, a vertical bore extending upwardly from said horizontal outlet passage to the top of the pump block and having a portion communicating with said cylinder, an inlet check valve for the high pressure pump in said bore below said sleeve, an 'outlet check valve for the high pressure pump in said bore above said sleeve and adapted to seat against a step in said bore, and means for varying the effective Volume of fluid discharge' by the high pressure pump comprising a rod fitted loosely in said vertical bore above said outlet valve, and a screw device at the upper end of said bore operable to limit the upward movement of the rod and 'the valve.

6. A pumping apparatus comprising, in combination', a casing forming a reservoir open at the top,:a "pump block having a horizontal portion forming a top 'plate for the reservoir, a portion depending therefrom into the reservoir, and a pair of vertically spaced lateral extensions on said depending portion provided with aligned vertical bores, a motor mounted on said top plate and having a shaft extendng down through said bores and to a position adjacent the bottom of the reservoir, bearings for said shaft mounted in said bores, a rotary low pressure pump supported on the bottom surface of the lower extension and driven by said shaft, said low pressure pump having an inlet port communicating with the reservoir and an outlet passage extending horizontally'through said depending portion of the pump block, a high pressure piston pump comprising a cylinder sleeve located in a bore extending horizontally through the pump block and parallel with said outlet passage, a piston operable in said sleeve, an eccentric carred on said shaft intermediate said extensions for actuating said piston, a vertical passage extending upwardly from said horizontal outlet passage to the top of the pump block and having portions passing through said cylinder sleeve, an inlet check valve for the high pressure punp in said vertical passage below said sleeve, an outlet check valve for the high pressure pump in said vertical passage above said sleeve and adapted to seat against a step in said passage, and means operable When the ,pumping apparatus is stopped for releasing fluid from the vertical passage to the reservoir, comprising a bypass port in said pump block leading from said vertical passage, a by-pass valve for controlling said by-pass port, a lever pivotally mounted on the pump block and carrying an adjustable screw engaging said by-pass valve to close said by-pass port, a hollow piston engaging the other end of said lever to close said by-pass valve and slidably mounted in a cylinder bore in the lower portion of the pump block and connecting with the low pressure pump outlet passage, a spring operable to pivot the lever to release said by-pass valve, a port in the end wall of said piston terminating externally of the pump block, a valve in the piston operable by low pressure fluid to close said port when the pumping apparatus is Operating, and a spring urging said piston valve to ojpenposition.

7. A pump, comprising, in combinaton, means providing a pump cylinder, a pump piston reciprocable in the cylinder, means for reciprocating the piston, an inlet passage leading to the cylinder and having an inlet check valve theren, an outlet passage leading from the cylinder, an outlet valve in the outlet passage including a valve seat and a check valve member movable relative to the seat along the passage by fluid in the passage, said valves being arranged so that the inlet valve opens and the outlet valve closes on intake strokes of the piston, and the inlet valve closes and the outlet valve opens on the pumping strokes of the piston, stop means limiting opening movement of the outlet valve member, and means for adjusting the stop means to vary valve member travel during operation 'of the pump, thereby to increase effective pump discharge Volume as valve member travel is reduced and decrease effective pump dscharge Volume as valve member travel, is increased.

8. A pump, comprisng, in combination, a reservoir,-a pump block, means providing a pump cylnder in the block, a piston reciprocable in the cylinder, means for recprcatng the piston, an inlet passage connecting the reservor and ,thecylinder and having inlet check valve means theren, an outlet passage leading upwardly from the cylnder, anzoutlet valve in the outlet passage including' a valve seat and a ball check valve member movable relative to the seat along the passage by fluid in the pas sage, the inlet valve opening and the outlet valve closing on intake strokes of the piston, and the inlet valve closing and the o'tlet valve opening on pmping strokes of the piston, a stop rod in the outlet passage in the path of ball member movement to limit the latter, and means for adjusting the rod to vary ball member travel during operation of the pump thereby to vary eective purnp discharge Volume.

ReferecsCited in the file of this patent 1', o os,559 1,146,133 1,930,293

UNITED STATES PATENTS Petsche Nov. 14, 1911 Carter July 13, 1915 Valentine Oct. 10, 1933 Hartman Jan. 16, 1934 Linders May 22, 1934 Parsons Jan. 22, 1946 Towler Dec. 8, 1953 Harrigan Jan. 17, 1956 Mann May 20, 1958 Gondek 4 Sept. 11, 1962 FOREIGN PATENTS France June 6 1949 

7. A PUMP, COMPRISING, IN COMBINATION, MEANS PROVIDING A PUMP CYLINDER, A PUMP PISTON RECIPROCABLE IN THE CYLINDER, MEANS FOR RECIPROCATING THE PISTON, AN INLET PASSAGE LEADING TO THE CYLINDER AND HAVING AN INLET CHECK VALVE THEREIN, AN OUTLET PASSAGE LEADING FROM THE CYLINDER AN OUTLET VALVE IN THE OUTLET PASSAGE INCLUDING A VALVE SEAT AND A CHECK VALVE MEMBER MOVABLE RELATIVE TO THE SEAT ALONG THE PASSAGE BY FLUID IN THE PASSAGE, SAID VALVES BEING ARRANGED SO THAT THE INLET VALVE OPENS AND THE OUTLET VALVE CLOSES ON INTAKE STROKES OF THE PISTON, AND THE INLET VALVE CLOSES AND THE OUTLET VALVE OPENS ON THE PUMPING STROKES OF THE PISTON, STOP MEANS LIMITING OPENING MOVEMENT OF THE OUTLET VALVE MEMBER, AND MEANS FOR ADJUSTING THE STOP MEANS TO VARY VALVE MEMBER TRAVEL DURING OPERATION OF THE PUMP, THEREBY TO INCREASE EFFECTIVE PUMP DISCHARGE VOLUME AS VALVE MEMBER TRAVEL IS REDUCED AND DECREASE EFFECTIVE PUMP DISCHARGE VOLUME AS VALVE MEMBER TRAVEL IS INCREASED. 